TasNetworks has published the Project Specification Consultation Report (PSCR) for Meeting Network Planning Requirements at George Town. Publication of this PSCR represents the first step in the Regulatory Test for Transmission (RIT-T) process.
George Town Substation is the sole substation supplying the George Town area. It is the connection point for generation and Basslink, the HVDC interconnector which links the Tasmanian and Victorian networks. It also supplies transmission connected customers at Bell Bay, a major industrial area in Tasmania.
The Australian and Tasmanian Governments have agreed to develop Bell Bay as one of Australia’s first Hydrogen Hubs. This follows the Tasmanian Government publishing the Tasmanian Renewable Hydrogen Action Plan (TRHAP) in 2020 that envisions Tasmania as a major producer and exporter of hydrogen by 2030. In response, TasNetworks received a number of connection enquires from proponents seeking to establish hydrogen production facilities in Bell Bay, supplied out of George Town Substation.
As load increases at George Town, issues begin to emerge on the shared transmission network. Specifically, the power system begins to approach operating conditions that are no longer compliant with the minimum network performance requirements outlined in the Electricity Supply Industry (Network Planning Requirements) Regulations 2018 (NPR). In particular, following the connection of an additional 210 MW of new load at George Town Substation, a single asset failure may be capable of resulting in a black system (defined as loss of 60% or more of Tasmanian regional load). Specifically, system black may occur following:
- a catastrophic failure of one of the network transformers or 220 kV bus (during a planned outage of the other bus) at George Town Substation, resulting in an outage of the entire substation; or
- a fault event caused by a single asset failure (e.g. transmission line or tower failure) severely impacting the stability of the voltage waveform, leading to undamped oscillation and cascading failure of the network.
TasNetworks has identified one integrated solution to address both aspects of the identified need, which comprises the following augmentation works:
- Reconfiguration of the existing 220 kV switchyard at George Town Substation;
- Establishment of a new 220 kV switchyard connected to George Town Substation to facilitate new connections; and
- Installation of dynamic reactive support.
TasNetworks is also actively considering whether non-network options could form part of a potential solution to assist in managing the emerging network risks from new load connections at George Town.
To be considered acceptable solutions to address the identified need, non-network options would need the following characteristics:
- Reduce the percentage ratio of George Town substation load of the total network load; and/or
- Offset the stability impacts to the network brought about from new load connections to the network.
TasNetworks is seeking stakeholder submissions on the various issues and credible option that have been presented as part of this PSCR over a 13-week period ending 28 February 2025. We are particularly interested in submissions from potential non-network service providers.
In accordance with the requirements of the Rules, a summary of the Project Specification Consultation Report is made available on the AEMO website. A copy of the PSCR can be obtained from TasNetworks’ website or by emailing regulation@tasnetworks.com.au.